| 摘要 |
<p>PROBLEM TO BE SOLVED: To perform light control of an LED delicately with high efficiency using a DC/DC converter. SOLUTION: A power supply, an inductor and a switching element are connected in series, an output voltage boosted through the inductor is taken out by switching the switching element and a light emitting element is driven with that output voltage. In such a light emitting element driving circuit, light control of an LED can be performed delicately with high efficiency using a DC/DC converter by providing a first control system for turning the switching element off when a first detection resistor of low resistance detects a peak value of a current flowing through the switching element, and a second control system for detecting the average value of currents flowing through the LED detected by a second detection resistor of low resistance, comparing the average value with a predetermined reference level and controlling the switching element intermittently based on the difference thus obtained.</p> |
